PPT-Introduction to Trusses

What is a truss A truss is a structural unit made from straight bars that form triangles or other stable rigid shapes The simplest form of a truss is one single triangle  . Roof structures. Although, theorists tried, most roofs until the 20. th. century involved a sloping pitch.. 40˚ or greater is a steeply pitched roof. 35˚ or less is a normal pitched roof. 20˚ or less is a normal pitched roof. Some examples of trusses. 2.1 (a) Find the forces in AB AD and AC in the following Figure E2.1. (b) Find the forces in EG FG and FH in the following Figure E2.1. Figure E2.1FBD Chapter 7. University of Engineering & Technology, Taxila. 1. Properties of Trusses. . Truss is a frame structure in which all the members have axial forces due to the following facts:. Members are arranged in triangles for stability.. Walls. Exterior Walls in Elevation: see Materials & Bldg. shape. Roof is 8:12 Pitch /or slope Cladding is drawn as Brick & Stucco siding. 12. 8. Roof slope. Bear. Rafters. Roof framing supports - give roof profile/shape. Objectives. The student will:. Understand the importance of ventilation.. Be able to identify when and where to ventilate. . Understand the dangers of ventilation.. Be able to identify the different types of roof construction.. September 8 – 11, 2015. Started: 9/8/15 . CLASSWORK. In CORNELL note style, copy the six vocabulary terms and definitions from NOS 21 to Activity #. 6 Definitions have been added in the next slide. Wood Floor and . Roof Trusses. Overview. Revised . 3/23/2017. SBCA.  has been the voice of the structural building components industry since 1983, providing educational programs and technical information, disseminating industry news, and facilitating networking opportunities for manufacturers of roof trusses, wall panels and floor trusses. . Overview. Revised . 3/23/2017. SBCA.  has been the voice of the structural building components industry since 1983, providing educational programs and technical information, disseminating industry news, and facilitating networking opportunities for manufacturers of roof trusses, wall panels and floor trusses. . Folks, I just received a rather disturbing series of pictures of new construction currently going on in New Jersey.    Apparently these new-style wood trusses are commercially available and no longer use the metal "gusset plates" that we are all familiar with. This new breed of firefighter-killers is simply 2x4 Finger Jointed lumber (yeah, it's not even dimensional lumber) held together by little spots of glue where the webs meet the chords. Check out the attached pics... You also can see that these particular trusses are installed in townhouse-style occupied multiple dwellings. All that's holding them up is a 2x8 or TJI sill plate that's anchor bolted to the block sidewall.    I'm not an engineer, but it looks like it's actually the dead load and   live load from above that holds the house of cards together. My dad is a commercial sales manager at a large lumberyard. He is going to further investigate the manufacture and engineering of this product and I'll keep you advised of anything important to our operational safety.   If a standard gusset-plated truss will fail in less than five minutes of fire exposure, how long will these toothpicks stand up? How about the added weight of 2 or 3 firefighters with equipment trying to make a vent hole and removing some of the engineered dead load providing the stability to the system?  Just food for thought. This stuff's out there... It's just a matter of   time 'til it pops up around here. Many nationally recognized instructors are now recommending popping a decent-sized inspection hole in the ceiling immediately inside the point of entry and on each floor of any building with smoke or fire . Roof Trusses. Trusses . are . triangular frame. works, consisting of . axially . loaded members . They . are . more efficient in resisting external loads. . as the . cross . section of . all the members . Overview. Revised . 2/2. /2017. SBCA.  has been the voice of the structural building components industry since 1983, providing educational programs and technical information, disseminating industry news, and facilitating networking opportunities for manufacturers of roof trusses, wall panels and floor trusses. . In-Class Activities. :. Check Homework, if any. Reading Quiz. Applications. . Simple Trusses. . Method of Joints. . Zero-Force Members. Concept Quiz. Group Problem Solving. Attention Quiz. Today’s Objectives. University of Engineering & Technology, Taxila. 1. Prof Dr Z. A. Siddiqi. LOADS. ON TRUSS ROOF. . All the gravity or vertical loads acting on the building trusses are first calculated in terms of the loads acting per one square meter of the horizontally projected area (plan area) having the units kg/m. Fall . 2012 . – J. Liu. Wood Beams: Additional Components. Wood Beams: Additional Components. Lumber Roof and Floor Decking. Fabricated Wood Components. Structural Composite Lumber (SCL). Laminated veneer lumber (LVL).